1 files changed, 276 insertions, 0 deletions

diff --git a/arch/sh/kernel/io_trapped.c b/arch/sh/kernel/io_trapped.c
new file mode 100644
index 000000000000..86a665d92201
--- /dev/null
+++ b/arch/sh/kernel/io_trapped.c
@@ -0,0 +1,276 @@
+/*
+ * Trapped io support
+ *
+ * Copyright (C) 2008 Magnus Damm
+ *
+ * Intercept io operations by trapping.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bitops.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <asm/mmu_context.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/io_trapped.h>
+
+#define TRAPPED_PAGES_MAX 16
+
+#ifdef CONFIG_HAS_IOPORT
+LIST_HEAD(trapped_io);
+EXPORT_SYMBOL_GPL(trapped_io);
+#endif
+#ifdef CONFIG_HAS_IOMEM
+LIST_HEAD(trapped_mem);
+EXPORT_SYMBOL_GPL(trapped_mem);
+#endif
+static DEFINE_SPINLOCK(trapped_lock);
+
+int __init register_trapped_io(struct trapped_io *tiop)
+{
+        struct resource *res;
+        unsigned long len = 0, flags = 0;
+        struct page *pages[TRAPPED_PAGES_MAX];
+        int k, n;
+
+        /* structure must be page aligned */
+        if ((unsigned long)tiop & (PAGE_SIZE - 1))
+                goto bad;
+
+        for (k = 0; k < tiop->num_resources; k++) {
+                res = tiop->resource + k;
+                len += roundup((res->end - res->start) + 1, PAGE_SIZE);
+                flags |= res->flags;
+        }
+
+        /* support IORESOURCE_IO _or_ MEM, not both */
+        if (hweight_long(flags) != 1)
+                goto bad;
+
+        n = len >> PAGE_SHIFT;
+
+        if (n >= TRAPPED_PAGES_MAX)
+                goto bad;
+
+        for (k = 0; k < n; k++)
+                pages[k] = virt_to_page(tiop);
+
+        tiop->virt_base = vmap(pages, n, VM_MAP, PAGE_NONE);
+        if (!tiop->virt_base)
+                goto bad;
+
+        len = 0;
+        for (k = 0; k < tiop->num_resources; k++) {
+                res = tiop->resource + k;
+                pr_info("trapped io 0x%08lx overrides %s 0x%08lx\n",
+                       (unsigned long)(tiop->virt_base + len),
+                       res->flags & IORESOURCE_IO ? "io" : "mmio",
+                       (unsigned long)res->start);
+                len += roundup((res->end - res->start) + 1, PAGE_SIZE);
+        }
+
+        tiop->magic = IO_TRAPPED_MAGIC;
+        INIT_LIST_HEAD(&tiop->list);
+        spin_lock_irq(&trapped_lock);
+        if (flags & IORESOURCE_IO)
+                list_add(&tiop->list, &trapped_io);
+        if (flags & IORESOURCE_MEM)
+                list_add(&tiop->list, &trapped_mem);
+        spin_unlock_irq(&trapped_lock);
+
+        return 0;
+ bad:
+        pr_warning("unable to install trapped io filter\n");
+        return -1;
+}
+EXPORT_SYMBOL_GPL(register_trapped_io);
+
+void __iomem *match_trapped_io_handler(struct list_head *list,
+                                       unsigned long offset,
+                                       unsigned long size)
+{
+        unsigned long voffs;
+        struct trapped_io *tiop;
+        struct resource *res;
+        int k, len;
+
+        spin_lock_irq(&trapped_lock);
+        list_for_each_entry(tiop, list, list) {
+                voffs = 0;
+                for (k = 0; k < tiop->num_resources; k++) {
+                        res = tiop->resource + k;
+                        if (res->start == offset) {
+                                spin_unlock_irq(&trapped_lock);
+                                return tiop->virt_base + voffs;
+                        }
+
+                        len = (res->end - res->start) + 1;
+                        voffs += roundup(len, PAGE_SIZE);
+                }
+        }
+        spin_unlock_irq(&trapped_lock);
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(match_trapped_io_handler);
+
+static struct trapped_io *lookup_tiop(unsigned long address)
+{
+        pgd_t *pgd_k;
+        pud_t *pud_k;
+        pmd_t *pmd_k;
+        pte_t *pte_k;
+        pte_t entry;
+
+        pgd_k = swapper_pg_dir + pgd_index(address);
+        if (!pgd_present(*pgd_k))
+                return NULL;
+
+        pud_k = pud_offset(pgd_k, address);
+        if (!pud_present(*pud_k))
+                return NULL;
+
+        pmd_k = pmd_offset(pud_k, address);
+        if (!pmd_present(*pmd_k))
+                return NULL;
+
+        pte_k = pte_offset_kernel(pmd_k, address);
+        entry = *pte_k;
+
+        return pfn_to_kaddr(pte_pfn(entry));
+}
+
+static unsigned long lookup_address(struct trapped_io *tiop,
+                                    unsigned long address)
+{
+        struct resource *res;
+        unsigned long vaddr = (unsigned long)tiop->virt_base;
+        unsigned long len;
+        int k;
+
+        for (k = 0; k < tiop->num_resources; k++) {
+                res = tiop->resource + k;
+                len = roundup((res->end - res->start) + 1, PAGE_SIZE);
+                if (address < (vaddr + len))
+                        return res->start + (address - vaddr);
+                vaddr += len;
+        }
+        return 0;
+}
+
+static unsigned long long copy_word(unsigned long src_addr, int src_len,
+                                    unsigned long dst_addr, int dst_len)
+{
+        unsigned long long tmp = 0;
+
+        switch (src_len) {
+        case 1:
+                tmp = ctrl_inb(src_addr);
+                break;
+        case 2:
+                tmp = ctrl_inw(src_addr);
+                break;
+        case 4:
+                tmp = ctrl_inl(src_addr);
+                break;
+        case 8:
+                tmp = ctrl_inq(src_addr);
+                break;
+        }
+
+        switch (dst_len) {
+        case 1:
+                ctrl_outb(tmp, dst_addr);
+                break;
+        case 2:
+                ctrl_outw(tmp, dst_addr);
+                break;
+        case 4:
+                ctrl_outl(tmp, dst_addr);
+                break;
+        case 8:
+                ctrl_outq(tmp, dst_addr);
+                break;
+        }
+
+        return tmp;
+}
+
+static unsigned long from_device(void *dst, const void *src, unsigned long cnt)
+{
+        struct trapped_io *tiop;
+        unsigned long src_addr = (unsigned long)src;
+        unsigned long long tmp;
+
+        pr_debug("trapped io read 0x%08lx (%ld)\n", src_addr, cnt);
+        tiop = lookup_tiop(src_addr);
+        WARN_ON(!tiop || (tiop->magic != IO_TRAPPED_MAGIC));
+
+        src_addr = lookup_address(tiop, src_addr);
+        if (!src_addr)
+                return cnt;
+
+        tmp = copy_word(src_addr,
+                        max_t(unsigned long, cnt,
+                              (tiop->minimum_bus_width / 8)),
+                        (unsigned long)dst, cnt);
+
+        pr_debug("trapped io read 0x%08lx -> 0x%08llx\n", src_addr, tmp);
+        return 0;
+}
+
+static unsigned long to_device(void *dst, const void *src, unsigned long cnt)
+{
+        struct trapped_io *tiop;
+        unsigned long dst_addr = (unsigned long)dst;
+        unsigned long long tmp;
+
+        pr_debug("trapped io write 0x%08lx (%ld)\n", dst_addr, cnt);
+        tiop = lookup_tiop(dst_addr);
+        WARN_ON(!tiop || (tiop->magic != IO_TRAPPED_MAGIC));
+
+        dst_addr = lookup_address(tiop, dst_addr);
+        if (!dst_addr)
+                return cnt;
+
+        tmp = copy_word((unsigned long)src, cnt,
+                        dst_addr, max_t(unsigned long, cnt,
+                                        (tiop->minimum_bus_width / 8)));
+
+        pr_debug("trapped io write 0x%08lx -> 0x%08llx\n", dst_addr, tmp);
+        return 0;
+}
+
+static struct mem_access trapped_io_access = {
+        from_device,
+        to_device,
+};
+
+int handle_trapped_io(struct pt_regs *regs, unsigned long address)
+{
+        mm_segment_t oldfs;
+        opcode_t instruction;
+        int tmp;
+
+        if (!lookup_tiop(address))
+                return 0;
+
+        WARN_ON(user_mode(regs));
+
+        oldfs = get_fs();
+        set_fs(KERNEL_DS);
+        if (copy_from_user(&instruction, (void *)(regs->pc),
+                           sizeof(instruction))) {
+                set_fs(oldfs);
+                return 0;
+        }
+
+        tmp = handle_unaligned_access(instruction, regs, &trapped_io_access);
+        set_fs(oldfs);
+        return tmp == 0;
+}